From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f194.google.com (mail-pf1-f194.google.com [209.85.210.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2BD911DDA18 for ; Fri, 3 Apr 2026 03:50:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.194 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775188236; cv=none; b=U9kUzAjIHan/+LekuyDYstJfQAgKDr+8BHKsSwlKw8HqvfivAP5ogqeGKIDSemLRJSOgXB73vYWbF5/XQH7qvn68r0U+DLSDp09SaS3MmYKDxGouyLvBNdA35nqVkhI4hORYT0+R7MfOBP59baYzaNbE+zxyOB8d49Xqqn77AVs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775188236; c=relaxed/simple; bh=Pfn9bRWTedzVSI69ZNxL1An1+0bxv8H8b4/2TDk4z04=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=bx+5kh62bpOfgd2Qx2w4KgF4lTcZGOVp9uANgfkrFHXwvVh9G+NFILZ/ZlWtlzgZheKtNw22ZqznHBzBtipl+UxeqEsJQPhKp+1WTdvsWNFkv9TmG/YipizXILxeIuke2y7bAE9tf+9tZf74XWGZEywEqCQJuySnRAPtQQcYBHE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Cc7vhvzy; arc=none smtp.client-ip=209.85.210.194 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Cc7vhvzy" Received: by mail-pf1-f194.google.com with SMTP id d2e1a72fcca58-82a893d289bso719841b3a.0 for ; Thu, 02 Apr 2026 20:50:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775188234; x=1775793034; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=HQPI3LrOqxlbsCY21LUJwyhyqeC+P+kOUutUODQJ9hw=; b=Cc7vhvzy1EcA3jz1yYoI160UQPm6QXK47W2sECgN5zFR7WIvzQUZYvy3aLPV5gft3V 2K1r0Ov1+MY5wkD3LhYmEvZVcOLzQIQBjhseoWOBnE2qcaNdr3XdbmFpcbmYoRdy2F+O vDGT0G+13SRwx2rVXLpv4y9DTugrdTxLaiCf1UBbRfMS0mwwpvpdejLRxjILSvf/i9BC TTT4DSi2TCP5EA1lOZ9VE48tQfoc+84wnAOFE7qqgC0bFFizJSedTpUKuRqVFSTxGTRG p2O0sWcp39J0g2qKS9IWa1KTGo6z7G3KN0XRXmn7UETlpvgqmGCvwzCWbXdXofqV9BcN zXng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775188234; x=1775793034; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=HQPI3LrOqxlbsCY21LUJwyhyqeC+P+kOUutUODQJ9hw=; b=aYfre3TFBRgKCfaEEjF3X0NI/Bqu0ocxHaVth/qyr143PrdUg/RoQGL1rHQGicZkaV w1Colbf4Gu7O2f4ksX6ckr6216jkIFl1skpa+Mmg6ENGRSP8Jx2dtiVIFna6IJHc8+TH j4LGOHK9FmT7LXegLUwfiJnCPGBudK9ab1sKi0IO6/IL/6xhMoQRXfShraaDvTJxT7Mi cVkAg6IO2KQSstGpzKus2jGanxL2LcU2Ahfc5CVw5SNk15WYdDIrjD627ui4+T4h/oDD +Q6spXdwYpr9l6n2gjs/7LWXPTQrIkMRX4bCh9wHkiRvqcfiGZEF9h3WPI8Ig/vLAtz8 qdFQ== X-Forwarded-Encrypted: i=1; AJvYcCXbhM11JPC83MnFb9/dgg2+S8hLGwHJ7vKVbUCHGvc8XHAYiG+WXK6a6Rm/dX6tNoLD7jYqIzxH2Gyw13g=@vger.kernel.org X-Gm-Message-State: AOJu0YwtyW9cAS8OFdxy9cY/wiRnejyIdEAwUmZ5wozhw5DMCZN4GDI7 YagdbqW0xLvpAMEaPhTXtjvzGFfIG1jUaKPquRPkxF3g317r3rAHJabFbreTVMRr2o0= X-Gm-Gg: ATEYQzyILUKch3B+I3eUBqpnqmsHrs5KWvuQn8Ot6V9g5OsVknT16kKLj/5xSlpAjGV aQgPqG1DCbkH6zqU9NWvqdaeGR/dIVG78dpnqOm4rCKUia3BcN+qRvpaOBMt+Z8N+tq8HWABrqA 0ZmnSLUjg/CNdHh0KVbs8C4g4i0E5OKxPaBKmH0JbYrZSDvkluIuKkAzXfrHFhnjnvIH1fi10Qk M+FVixJua73YDvSojtMNpkXmNtStrdgKkLcbN2qhL42fZto8SEU2Okka49e7kyW46wzSpeCCiZB ZlhFmst/MjKd+6q9FF7lMLwuQRUVSNWgqEAdF21wTQmVPVixTO1204Zl2Jl7DhceSOloA14aba3 bjRYrEADyFoKviEc559LxnX0n9n17E5lA5eSGUaStWduDMwwSma+UBJhVuDwSQaZTzO3nTayHEf n9DxVeqf4K3hTmc7wnSEAt3YEpYAGJxON3dMvA9ATGqWUz4s+bJWA9O3TIHY75 X-Received: by 2002:a05:6a00:4fc6:b0:827:3ff6:fb72 with SMTP id d2e1a72fcca58-82d0dbc3143mr1571310b3a.51.1775188234433; Thu, 02 Apr 2026 20:50:34 -0700 (PDT) Received: from lima-ubuntu.hz.ali.com ([47.246.98.223]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82cf9c9cbf6sm4919005b3a.52.2026.04.02.20.50.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Apr 2026 20:50:34 -0700 (PDT) From: Qing Wang To: zhangdandan@uniontech.com Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzbot+37b7f6cd519f7fb8d32a@syzkaller.appspotmail.com, urezki@gmail.com, wangqing7171@gmail.com Subject: Re: [PATCH] mm/vmalloc: fix KMSAN uninit-value warning in decay_va_pool_node() Date: Fri, 3 Apr 2026 11:50:27 +0800 Message-Id: <20260403035027.2052972-1-wangqing7171@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Fri, 03 Apr 2026 at 11:30, Morduan Zang wrote: > While adding INIT_LIST_HEAD(&va->list) in alloc_vmap_area() would indeed > silence the KMSAN warning, I'm concerned that it might only be masking > a deeper issue rather than fixing the root cause. > > It seems that the uninitialized access in decay_va_pool_node() suggests > a potential race condition where nodes from a concurrently repopulated > pool might be lost or the list structure could be incorrectly overwritten > during list_replace_init(). > > Instead of just initializing the list head to satisfy KMSAN, should we > consider modifying decay_va_pool_node() to avoid using list_replace_init() > which might drop concurrent repopulate nodes? Perhaps using list_splice() > or a proper merge of the leftover VAs would be a more robust fix for > the underlying synchronization issue. Thank you very much for the reminder. I realized that my patch does not fix the real issue(concurrent corruption of the list). Please ignore this patch and let's focus on analyzing this concurrency issue. --- Best Regards, Qing